Young families have long seen the benefits of living with others at a similar life-stage out in the leafy suburbs – earning Wandsworth and Clapham in south-west London the nickname "Nappy Valley". Now though, the rising age of first-time buyers – 37 for those buying without financial help from family or friends – is starting to have a knock-on effect on where young professional couples opt to exchange chic city-living and loft apartments for small children, gardens and the latest buggies.

The interval between the first step on the ladder and the sounds of the patter of tiny feet is closer than ever. And with housing costs causing 24 per cent of 18- to 34-year-olds to delay having children according to a survey by housing charity Shelter, when buyers do make a purchase they are causing mini baby booms in unexpected locations.

"Wandsworth it is the original, and best nappy valley," says Luke Pender Cudlip of estate agents Knight Frank, "and with good reason. There are plenty of open spaces around the area – play parks and duck ponds – and there is a great selection of very good state as well as private schools."

The area's strong social networks are also a draw for young families. "Even if you don't know people in the area when you buy, you soon will when there's a plethora of children's and mothers' groups and clubs, and you don't have to take the car when you are taking the kids out," adds Pender Cudlip.

While Judy Voisey, an agent at Cluttons' Clapham branch cites "an abundance of family homes, as well as good shopping and family-friendly eating."

While Wandsworth and its environs may be the original nappy valley, it is now unaffordable for all but the wealthiest first-time buyers. And baby booms are instead being seen at several other, more affordable, locations across the country. Gary Ennis, a Regional Managing Director for developer Barratt Homes says, "At Watercolour in Redhill, Surrey, for example, there has been a very obvious rise in sales to growing families. The local midwife has even asked for a map of the development as so many expectant mothers have moved there."

The stork has also been delivering enthusiastically at several of house builders David Wilson's developments, including Hamlet Place in Tipton in the West Midlands, where some 250 homes are being built close to shops, parks and schools, with three-bedroom houses starting from £149,950 and four-bedroom detached from £249,9950.

In north-west London Derrick Deysel, wife Sallie and daughters Lyla, three, and Kiki, one, moved to The Ridgemont development in Mill Hill, just down the road from the shops and eateries on the Broadway. "The area is renowned for its great schools. There is a real sense of community, and a playground will be built on the development soon so our children will be secure here playing in the street with the other kids when they are olde," says Derrick.

Ridgemount is a joint venture by Countryside Properties and Annington Homes, and houses aimed at young families will go on the market later this year, priced from £550,000.

Outside of the capital the eastern part of the country is the most fertile hunting ground for those seeking a new nappy valley. Cambourne in Cambridgeshire has lured so many young couples that it has attracted headlines for a CBR (births per thousand population) that rivals China, India and Brazil.

It's easy to commute from there to the hi-tech businesses of "Silicon Fen", as well to Cambridge, St Neots and Peterborough, with a family-work balance another vital element for a successful nappyvalley.

Neville Stebbing, project director of the Cambourne developer Consortium, says: "Cambourne has been deliberately designed to encourage the evolution of a strong community, and buyers find a ready-made social network which is very important, especially for the mothers of young children, who could otherwise feel quite isolated in a new community."

As well as community centres and sports pitches, there's a medical practice, a third primary school to keep pace with the demand from new entrants, a family-friendly pub, a supermarket and petrol station, and a high street with a chemist, dry cleaner, restaurant and a clutch of takeaways.

Several house builders are selling homes at Cambourne. Prices at Bryant's Churchill Gardens start from £174,995, and at Taylor Wimpey's Greenfield's Park from £192,995. At Bovis Homes' Serpentine Walk, prices start from £209,950 for a three-bedroom home and £249,950 for a four-bedroom home. "A key attraction for those with family commitments are the low property prices compared with other places such as Cambridge," says Stebbing. Elsewhere in the county demand is growing fast, with towns such as Peterborough experiencing massive population growth due in part to its economy and good transport links.

Research conducted for the BBC, "Changing UK", showed Cambridgeshire to have the highest population increase of any county between 1981-2006 – and the County Council estimates that the county's population will have grown by another 33 per cent by 2021.

In the Midlands,Telford, the largest town in Shropshire, is one of the fastest-growing towns in the UK. And its population of 140,000 is projected to exceed 200,000 within 20 years. Ironstone, a development in the heart of Lawley, Telford, will create 3,300 new homes and a community, built by a partnership between the UK's largest house builders, Barratt Homes, Taylor Wimpey and Persimmon. They will be developing a collection of four distinct and unique neighbourhoods surrounding Lawley Square, the commercial and social hub of the Ironstone community – a new nappy valley in the making?

If the trend towards more restrictive lending becomes firmly established in the UK, parks for toddlers to let off steam, parking for pushchairs in the hall, and the calibre of local pregnancy yoga classes will become increasingly important in attracting cost- conscious young families.

Happy families: Why Redhill ticks all the right boxes

After getting married, Chris and Laura Ottley wanted a home with space for a family. They moved to Barratts' Watercolour development in Surrey and now have a 5-month-old son, Lucas.

Laura, 32, says: "We moved here to start a family and it ticked all the right boxes. I'm not surprised Redhill has attracted so many young families like us. It feels like you are in the countryside but we are also close to the town, and the train station is handy – you can still get to work within an hour.

"The nursery is nearby, and the development has good facilities including a doctor's surgery and pharmacy, which is a real bonus when you have small children. I can imagine Lucas cycling around and really benefiting from the outdoors.

"There is a great community with a great social scene. We didn't know anyone when we moved here, but now we have a whole circle of friends, and there's always a party to go to."